Definition of Scattering Loss

Scattering losses in polymers arise from microscopic variations in the material density. When natural light of intensity /q passes through a distance y, and its intensity is reduced to I by the scattering loss, the turbidity t is defined as 

Because r corresponds to the summation of light scattered in all directions, it is given as 

By substituting Equations 2.14-2.16 into Equation 2.13, r can be rewritten as follows  

Eurthermore, the intensity of the isotropic light scattering, V °, and the anisotropic light scattering, Hy, can be expressed by Equation 2.18 [17] and Equation 2.19 [18], respectively, as 

Ag is the wavelength of light in vacuum, n is the refractive index, is the Boltzmann constant, T is the absolute temperature, 0 is the isothermal compressibility, N is the number of scattering units per unit volume, and 5 is the mean square of the anisotropic parameter of polarizabihty per scattering unit. Finally, from the definition of the turbidity t in Equation 2.12, the fight scattering loss (dB/km) is related to the turbidity t (cm ) by 

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